Tensile system of building construction



Dec. 20, 1966 c. E. ENTWISTLE 3,292,313

TENSILE SYSTEM OF BUILDING CONSTRUCTION Filed July 17, 1962 4 Sheets-Sheet 1 Suom SHUTTE/V/NG' mm H O @112 [1 I, l BA! G BAY F v BAY E Ce CQ'L INVENTOR.

Dec. 20, 1966 c. E. ENTWISTLE 3,292,313

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A frog/v United States Patent Ofifice PM 13, 6:

3,292,313 TENSILE SYSTEM OF BUHLDHNG CONSTRUCTION Clive E. Entwistle, 210 E. 58th St, New York, N.Y. 10022 Filed July 17, 1962, Ser. No. 210,487 7 Claims. (Cl. 52-74) This invention relates to building construction techniques, and more particularly to a novel method for erecting multiple-story structures and to buildings of exceptional design constructed thereby.

In conventional frame structures, whether of steel or concrete, vertical loads are normally transmitted by vertical columns from the floors, where they are generated, to the ground, where they are opposed. The interruptions afforded by the floors and the exigencies of transport necessitate that the structure be erected in sequential steps. That is, the foundation must first be laid, then the bottom floor set up, followed by erection of columns, then another floor and again columns, and so forth, until the roof is reached. One must therefore wait until a iioor is framed before erecting the next series of columns, and vice versa.

An exception to this ah'nost universal practice is provided by the lift slab principles, wherein whole floors are jacked hydraulically from the ground level where they are poured, to the higher level to which they are destined. However, the difficulty of framing the vertical columns requires a far stifier design than would otherwise be the case, to resist flexion during raising, and it also markedly limits the total number of floors that can be erected, which in practice rarely exceed ten.

This is due not only to the factor of the long unsupported column height, but also to the extreme slowness of the hydraulic jacking operation. Moreover, expensive control equipment is required to coordinate such jacking operations to avoid deformation of the floors during raising. The lift slab principle is therefore not feasible with high-rise buildings.

Thus with conventional techniques, the erection of high-rise structures, in the order of fifty stories, may take as long as twelve months or more to complete the structure, frame and floors.

In view of the foregoing, it is the main object of this invention to provide a novel and efficient technique for erecting multiple-story structures at an exceptionally rapid rate, so as to effect major savings in construction costs, and prevent loss of interest in invested capital.

More specifically, it is an object of the invention to provide a tensile system of building construction which makes possible the superposition of floors in space and their subsequent enclosure by methods, which:

(a) Permit continuous, uninterrupted and extremely rapid construction of the vertical load-bearing and lateral stiffening elements;

(b) Permit the pre-fabrication of floors in bay units and the raising of such units rapidly to any height, unlimited by considerations of column stiffness; and

(c) Permit the weather closure of the building by inexpensive methods and materials without prej-udicing the appearance of the building, in that the facade thereof is constituted by sunfoils or a variety of decorative panels supported on an external tensile screen spaced from and enveloping the weather closure.

Briefly stated, these objects are attained in a building comprising a central core or spine adapted to take all vertical compressive loads and to provide the stiffening needed for wind bracing. Stretched from a horizontal spreader platform disposed adjacent the top of the spine or from lateral projections, is "an array of vertical cables which form a vertical lattice or grid surrounding the spine to define an interior volume. Pre-assembled floor units are raised from the ground within the interior volume and are joined to the spine, to the tensile cables, as well as to each other, a combination of such units in a common horizontal plane constituting a complete floor. The operating sequence is such that first the top floor is completed, followed successively by the floors therebelow until the bottom floor is completed. A weather closure or skin is supported on the tensile cable grid. Optionally, an external decorative or open solar screen may be' supported on outer tensile cables stretching in {front of the building, either vertically or diagonally, the screen consisting of isolated elements of enameled metal, ceramic shapes, bronze, anodized aluminum, or other weather-resistant material. Such a screen will reduce solar heat loads and permit the use of extremely economical weather Walls such as concrete block, without loss of architectural or aesthetic quality.

For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description, to be read in conjunction with the annexed drawings, wherein:

FIG. 1 is an 'elevational view of the central cores of a twin building constructed in accordance with the invention; I

FIG. 2 is a plan view of the building;

FIG. 3 shows in elevation the top portions of the building tower and cable spreading platform;

FIG. 4 is a plan view of said top portions shown in FIG. 3;

FIG. 5 separately shows one of the cable fittings on the platform;

FIG. 6 is an elevational view of the same building with the tensile cables attached;

FIG. 7 is a plan view of one of the floor bay units;

FIG. 8 is a side view of the trolley beam used in conjunction With the floor bay unit;

FIG. 9 is an end view of the trolley beam;

FIG. 10 is a plan view showing a cable clamp for attaching the main beams of the adjacent floor bay units to the tensile cables;

FIG. 11 shows in elevation the manner of raising a floor bay unit;

FIG. 12 illustrates the completed building including an outer or facade screen; and

FIG. 13 is an enlarged view showing the manner of attaching solar and decorative reflector elements to the facade screen.

Referring now to FIGS. 1 and 2, there is shown an example of a building constructed in accordance with the invention, the building being constituted by twin towers having a pair of central cores or spines C and C preferably formed of concrete. The spines are adapted to take all vertical and compressive loads and to provide stiffening needed for Wind bracing. The building includes three basement levels, B B and B As best seen in FIG. 2, the spines C and C have an H-shaped configuration, although other plan configurations may be employed, depending upon requirements of space use. In the basement areas, lateral extensions C2 and C2 serve to reinforce and to anchor the spines. The spines are constructed rapidly by a continuous slip-forming process by means of sliding shuttering 10 of the type used, for example, in silo construction. Concrete, which may be of the high-strength type, together with reinforcement, is supplied to the shuttering by means of hoisting tackle 11 which raises and lowers a hopper 12. Concrete is poured into the hopper from a truck 13 which rides up ramp 14 at the building site. In practice, a forming speed of 2'6" per hour is normal for this type of equipment, so that it is possible on a continuous shift basis to erect a 600-foot spine, equivalent to .a fifty-story tower, in about ten days.

The hoisting tackle, upon completion of the core, is then used to raise winches and other equipment necessary to permit erection of construction hoists E and E within the spine alcoves, thus providing immediate access to all floors for the labor crew.

Surmounting each spine, as shown in FIG. 3, is a conical column 15, also formed by shuttering or fabricated in steel, which terminates in a crown 16. A horizontal platform 17 is constructed at the junction of the column and spine, the platform extending symmetrically from all sides of the spine to provide a spreader for tensile cables. Attached securely to the edges of the platform,

as well as at two equidistant positions intermediate these points, are cable mountings 18. Each mounting 18, as shown in FIG. 4, is constituted by a triangular mounting bracket whose base is bolted or otherwise aflixed to the platform, and a pair of cable-holding fittings 19 and 20 pivotally connected to the bracket by a link member 21. Alternatively, the cables may be passed continuously from ground over saddles on the top of the mast and back to ground.

Radiating downwardly and outwardly from the crown and coupled to the upper fittings 19 of the mountings on the platform, are twelve stub cables 22, while stretched vertically from the lower fittings 20 and anchored below the basement level of the building by adjustable fittings 23 (as indicated in FIG. 6), are twelve tensile cables 24. These cables are stressed by means of helical jacks to their ultimate design load so as to eliminate movement during subsequent floor erection. The tension is reduced by slackening the jacks in the measure that the floor dead load is applied, so that on completion the jacks impose no load.

Alternatively, in place of a spreader platform, outriggers provided with cable saddles may be used, with the tensile cables passed through the saddles over the tower, and ldown back to the ground level to obtain the same resu t.

The formation of tensile cables 24 constitutes a vertical lattice surrounding the spine of each tower, as illustrated in FIG. 6, the interior space between the spine and grid being the usable building area to be divided by floors.

The floors are each made up by eight rectangular bay units occupying contiguous positions within eight bay areas, Bay A to Bay H, about the spine. Each bay area lies under the platform 17 and is defined by a square section thereof whose dimensions correspond to those of the central spine. The floor bay units are either fabricated at the ground level where work can be more conveniently performed and under better control conditions than in upper floors as in the conventional practice, where all elements, beams, purlins, reinforcements, etc., must be hoisted to the operating level by crane. If desired, the floor bays may be fabricated under factory conditions and delivered to the building site fully or partly assembled.

Each floor bay unit 25, as shown in FIG. 7, is made up of a main outer beam 26 of steel to which is welded an array of secondary or cross-beams 27 extending perpendicularly from the main beam. The bay unit is covered by suitable deck beam 28 which may also be of steel. The bay unit is provided with a central opening 29 through which lifting cables may be passed.

In FIG. 7, the tensile cables 24 at the outer corners of the bay unit 25 are shown as actually made up of a cluster of three cables 24a, 24b and 24c, rather than as a single cable, due to the magnitude of the load. The corners are attached to these cables by complementary halfcable clamps 30.- In FIG. 7, the cluster of cables 24a 24b and 240 are shown clamped to the main I-beams 26 and 26' of two adjacent bay units, the outer surface of the beams adjoining a spandrel wall 31, which is of cellular concrete block or panel. Caulking 32 is provided at the wall junction. When the floor bay units are to be lifted, the cables act as guides, the half cable clamps permitting sliding movement up the cables. The clamps are thereafter tightened when the adjacent unit occupiesv its assigned position.

At the assigned position of the unit, the ends of the secondary beams 27, which engage the spine surface, are attached thereto by weld plates 33, bolts or other suitable means, hence there is no need for a main beam at the inner end of the unit. However, during lifting of the bay unit, it is necessary to provide a removable or trolley beam to permit the bay unit to ride against the spine: surface. This trolley beam 34, as shown separately in FIGS. 8 and 9, has several pairs of spaced brackets 35 mounted above its upper flange, each bracket being adapted to accommodate the end of a cross beam 27 of the bay unit. A locking wedge 36 which enters slots in the bracket serves to hold the cross beam temporarily in place.

The trolley beam 34 also includes a retractable wheel 39 adapted to ride horizontally on the lower flange 27a of the cross beam to permit withdrawal of the trolley beam by means of draw lines 41 (note FIG. 7) after the bay unit is in place. Rubber rollers 40 are rotatably mounted on the web of the trolley adapted to engage the surface of the spine and adapted to ride vertically therealong as the bay unit attached to the trolley beam is being raised.

The lifting cable 42 for the bay unit 25 passes through i the vertically aligned openings 29 in the higher units already in place and is connected by suitable linking hooks 43 to the bay unit in question. The connection of the unit to the concrete core may be made by bolting into prepared positions, or preferably, by welding to plates 33 fixed to the concrete core, this method allowing greater flexibility of position of the weld plates on the spine.

The adjustment of floor height prior to bollting and welding is made by temporary hangers 44 equipped with turnbuckles that are moved down from floor to floor by the erection crew. The lifting tackle 42 is now passed through the floor bay aperture and attached to the trolley beam which has previously been pulled by the draw lines 41 to a position under the aperture. The wheels on the trolley beam are now retracted and the trolley beam lowered for attachment to the next floor bay to be raised.

The eight bays constituting a complete floor are individually raised and connected to the spine and to each other as well'as to the cables, in the manner described hereinabove. In practice, erection time could be maintained at about one hour per bay, so that all floors in a fifty-story building could well be raised and attached in place in less than a months time, as compared to the many months involved with conventional techniques.

Services and cables are laid on the bay unit at ground 1 The weather closure of the building may be carried out by the cheapest available methods and materials, for the external appearance is determined by a second screen or grid of tensile cables 55, as shown in FIGS.

12 and 13, spaced from the first grid by Outriggers or other means projecting from the platform 17, the spacing between the inner and outer grids being maintained at each floor level by catwalks 56 or other suitable means. Attachable to the outer cables 55 are solar shielding elements or foils 57 which may be of various sizes and The invention is not limited to steel,

shapes, and materials, the elements extending laterally from the cables or being attached (longitudinally thereto or at angles, by suitable clamps. Alternatively, to the sun foils, diverse forms of decorative panels may be attached to the outer grid in a highly varied range of sizes, shapes and materials. The cable tension can be adjusted to allow limited movement due to wind, thus adding a dynamic element having architectural interest. The decorative and solar screen is erected Without any jointing. Outer access to the fixed glazing 58 on the inner grid may be had, for purposes of cleaning or repair, by means of the catwalks.

Thus the building constructed in accordance with the invention is constituted essentially by a self-supporting spine from whose zenith is supported an inner grid of tensile cables which are anchored at ground level and are spaced from the spine to define a building space within which floor units may be raised, beginning with the top level and working down, each unit being attachable to the spine and to the cables. A weather closure is formed on the floor perimeter, and a second lattice, also supported from the zenith of the spine and anchored on the ground, is erected to surround the inner grid and to support solar and decorative elements which make up the building facade.

While there has been shown what is considered to be a preferred embodiment of the invention, it will 'be obvious that many changes and modifications may be made therein Without departing from the essential spirit of the invention, as defined in the annexed claims.

What is claimed is:

1. A building structure comprising:

(a) a vertically extending spine adapted to take all vertical and compressive loads of the structure,

(b) a horizontal platform supported on said spine adjacent the upper end thereof,

(c) a grid surrounding said spine and constituted by an array of tensile cables extending vertically from the edge of said platform to anchor points in the ground, the area between said grid and said spine defining the building space,

(d) a series of floors Within said space supported by said spine and said cables, each floor being formed by a group of bay units which are secured to each other to define a multiple-bay floor which surrounds said spine and which occupies the space between said spine and said cables, and

(f) means connecting each multiple-bay floor to said cables and said spine.

2. A building structure as set forth in claim 1, wherein said spine has an H configuration adapted to take all vertical and compressive loads.

3. A building structure as set forth in claim 1 further including an outer screen of cables supported from said platform and spaced from said grid to support solar shielding elements.

4. A building structure as set forth in claim 1, where- .in said spine has an H-shaped configuration and is formed by reinforced concrete.

5. A building structure as set forth in claim 1, wherein said stub cables and tensile cables are attached to the edge of said platform by mounting brackets each having a pair of cable-holding fittings for connection to said associated stub and tensile cables.

6. A building structure as defined in claim 1, wherein each floor is constituted by interconnecting bay units each of which is made up of a main outer beam and an array of cross-beams extending perpendiculanly from the main beam.

7. A building structure, as set forth in claim 1 further including stub cables connecting the tensile cables at the edge of said platform to the peak of said spine.

References Cited by the Examiner UNITED STATES PATENTS 1,075,123 10/1913 Scheas 52--715 1,819,345 8/1931 Thurman 52-745 1,988,075 1/1935 Fiorini -2 52236 2,109,529 3/1938 Goddard 18936 X 2,294,554 9/ 1942 Henderson 52236 2,477,256 7/1949 Kneas 52220 3,028,707 4/ 1962 Sagalovitch 52-745 3,058,264 10/ 1962 Varlonga 52236 FOREIGN PATENTS 161,253 10/ 1951 Australia.

857,443 12/ 1952 Germany. 1,119,499 12/ 1961 Germany.

322,901 8/ 1957 Switzerland.

OTHER REFERENCES Popular Mechanics Publication, December 1959, page 113.

FRANK L. ABBOTT, Primary Examiner. JACOB L. NACKENOFF, Examiner.

J. L. RIDGILL, Assistant Examiner. 

1. A BUILDING STRUCTURE COMPRISING: (A) A VERTICALLY EXTENDING SPINE ADAPTED TO TAKE ALL VERTICAL AND COMPRESSIVE LOADS OF THE STRUCTURE, (B) A HORIZONTAL PLATFORM SUPPORTED ON SAID SPINE ADJACENT THE UPPER END THEREOF, (C) A GRID SURROUNDING SAID SPINE AND CONSTITUTED BY AN ARRAY OF TENSILE CABLES EXTENDING VERTICALLY FROM THE EDGE OF SAID PLATFORM TO ANCHOR POINTS IN THE GROUND, THE AREA BETWEEN SAID GRID AND SAID SPINE DEFINING THE BUILDING SPACE, (D) A SERIES OF FLOORS WITHIN SAID SPACE SUPPORTED BY SAID SPINE AND SAID CABLES, EACH FLOOR BEING FORMED BY A GROUP OF BAY UNITS WHICH ARE SECURED TO EACH OTHER TO DEFINE A MULTIPLE-BAY FLOOR WHICH SURROUNDS SAID SPINE AND WHICH OCCUPIES THE SPACE BETWEEN SAID SPINE AND SAID CABLES, AND (F) MEANS CONNECTING EACH MULTIPLE-BAY FLOOR TO SAID CABLES AND SAID SPINE. 